Azalea plant named ‘Robled’

ABSTRACT

A new and distinct variety of  Azalea  plant found as a branch sport of the  Azalea  hybrid ‘Conled’ U.S. Plant Pat. No. 10,568. The new variety possesses a unique blooming time and is superior in development of a low, dense, globose shaped plant with attractive large single multi-colored flowers.

Genus species: Rhododendron hybrid.

Varietal denomination: ‘Robled’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct variety of evergreen Azalea of the genus Rhododendron and a member of the Ericaceae family. This new Azalea variety, hereinafter referred to as ‘Robled’, was discovered by Robert Edward Lee in July, 1995 in Independence, La. ‘Robled’ originated as a naturally occurring branch sport of Azalea hybrid ‘Conled’ U.S. Plant Pat. No. 10,568 while it was being grown in Independence, La. The value of this new cultivar lies in its unique blooming period, bloom color, bloom form, bloom size, and growth habit.

Asexual propagation of the new plant by cuttings has been under Mr. Lee's direction at the same location. The new plant retains its distinctive characteristics and reproduces true to type in successive generations. The plant cannot be reproduced true from seed.

SUMMARY OF THE INVENTION

The following are the most outstanding and distinguishing characteristics of this new cultivar when grown under normal horticultural practices in Independence, La.

-   -   1. The unique spring, summer, and fall blooming.     -   2. Attractive flower color ranging from White Group 155D to Red         Group 56C.     -   3. Large, single flower with wavy petal margins. The flowers         range in size from 2½″-3″ in diameter.     -   4. Easily propagated with semi-hardwood cuttings in late spring         through the summer.     -   5. Fast growth rate under normal fetilization and moisture         conditions.     -   6. Low, dense and globose in nature.     -   7. Good specimen plant.     -   8. Desirable in planters.     -   9. Makes a very good hedge or screen.     -   10. Very good foundation plant.     -   11. Does well as an understory plant in a woodland garden.     -   12. Hardy to Zone 7.     -   13. Attracts butterflies.

DESCRIPTION OF THE DRAWINGS

This new Azalea hybrid variety is illustrated by the accompanying photographic prints in which:

1. The photograph at the top of the sheet is a close-up showing flower, foliage, and stem color as well as flower size and form.

2. The photograph at the bottom of the sheet shows the dense and globose growth habit of a young three gallon plant.

The colors shown are as true as is reasonably possible to obtain by conventional photographic procedures. Colors in the photographs may appear different than actual colors due to light reflectance. The colors of the various plant parts are defined with reference to The Royal Horticultural Society Colour Chart. Description of colors in ordinary terms are presented where appropriate for clarity in meaning.

BOTANICAL DESCRIPTION OF THE PLANT

The following is a detailed description of the new variety of Azalea based on my observations made of 2 year old plants grown in 3 gallon containers in wholesale commercial production practices, in greenhouses, and in established landscape plantings in Independence, La.

Distinctive Characteristics

TABLE 1 Characteristic ‘Robled’ ‘Conled’ PP#10568 Height (Mature) 3-4′ 3-4′ Width (Mature) 4-5′ 4-5′ Flower Diameter 2½-3″ 2½-3″ Flower Form Single Single Flower Color White G. 155D-Red G. 56C Red G. 48B Flower per Terminal 3-4 3-4 Bloom Period April April Bloom Period Early July > Frost Early July > Frost Hardy Zone 7 7 Stamen Number 5-9 5-9 R. oldhamii Characteristic ‘Fourth of July’ ‘White Gumpo’ Height (Mature) 8-10′ 2-3′ Width (Mature) 6-7′ 3-4′ Flower Diameter 1¾-2¼″ 2½-3″ Flower Form Single Single Flower Color Red G. 39A White G. 155D Flower per Terminal 2-4 1-4 Bloom Period Early July > Frost May Bloom Period Hardy Zone 7 6 Stamen Number 7-10 5

‘Robled’ originated as a branch sport of Azalea hybrid ‘Conled’ U.S. Plant Pat. No. 10,568 which was the result of Mr. Lee's planned cross hybridization between the Azalea ‘White Gumpo’ and Rhododendron oldhamii ‘Fourth of July’. The new variety differs from ‘Conled’ in its flower color which is White Group 155D to Red Group 56C rather than Red Group 48B.

Mr. Lee's hybridization program was conducted with emphasis on species that are not commonly found in the genetic make-up of the present day hybrids. The ‘Fourth of July’ cultivar is a heavy summer and fall blooming plant, not like the Rhododendron Species Foundation form. The flower buds form on new growth and start blooming about July 14. Mr. Lee used this cultivar to cross with existing hybrids which have a tendency to bloom in the fall and which are also fairly hardy. As expected, the resulting seedlings are heavy summer and fall bloomers with very impressive spring blooms also.

-   Classification: -   Botanical: Rhododendron hybrid ‘Robled’. -   Form: Low, dense, and rounded. -   Height: 3-4′. -   Width: 4-5′. -   Growth habit: Low, dense and globose. Fast growth rate under normal     fertilization and moisture conditions. -   Growth rate: In a period of six years from a rooted cutting the     plant reaches a height of 2 feet and a spread of 3 feet. The growth     rate is normally about 6 to 8″ per year; the plant reaches a height     of 3 to 4′ at maturity while maintaining a dense habit due to the     abundant branch development. -   Foliage: Alternate, simple, evergreen, pubescent, elliptic, and     varying in size from 1½″ to 1¾″ long and ½″ to {fraction (5/18)}″     wide. The margins are entire, with a petiole {fraction (3/16)}″ to     {fraction (5/16)}″ long. Midveins and laterals are impressed on the     upper leaf surface and prominent on the underside. The base of the     leaf is cuneate to attenuate and the apex is acute to mucronate. The     upper surface of the immature leaves is dull, pubescent, and is     Yellow-Green Group 144A and the underside is Yellow-Green Group     146D, pubescent, and matte. The upper surface of the mature leaves     is Yellow-Green Group 147A, dull and slightly pubescent and the     underside is Yellow-Green Group 146B, matte, and pubescent. The     immature petioles, midribs, and veins are Yellow-Green Group 146C.     New growth is pubescent. These hairs are initially soft and white     and cover both sides of the leaf with a higher concentration on the     petioles and veins. They are slightly curled, flat, and range in     length from {fraction (1/32)}″ to {fraction (3/32)}″. As the growth     matures much of the leaf pubescence is lost; however, the stems,     petioles, and leaf veins retain this pubescence which becomes more     setaceous and darker in color (Brown Group 200B) through the growing     season.

In 1998, the date of initial spring growth was March 5, in Independence, La. After the initial spring flush there was almost continuous growth until that fall ending November 5, also in Independence, La. When grown in full sun, the internode length of this plant is ¼″ to ½″; when grown in light shade the internode length is ⅜″ to ¾″. As would be expected a plant grown in shade results in a taller, less dense plant with larger leaves.

The average length of terminal growth of the initial spring flush is about 4″ for a plant in full sun and about 6″ when grown in shade. This growth should not be trimmed since it will produce flowers starting in early July. As the plant continues to grow through the summer and fall more flower buds are produced, which mature and bloom until frost. This remaining growth produces about 4″ to 5″ of height. As cool weather approaches, some of the flower buds become dormant. These buds bloom in April of the next year.

-   Stems: The young stems are Yellow-Green Group 146C and densely     clothed with spreading white glandular hairs. During the second     growing season they become Greyed-Green Group 197B, glabrous and     rugose. The pith is solid and uniform. Young and older stems are     densely branched. -   Buds: Tight buds at ½″ are ovate and acuminate Yellow-Green Group     146D with a hairy pubescence Brown Group 200A. The buds are borne in     clusters of 3 to 4, and are sheathed by a pair of modified leaf     bracts which are from ¼″ to ½″ long, persistent, and Yellow-Green     Group 147A. The pedicel is ⅜″ to ½″ long, pubescent, and Red Group     48A. The calyx is {fraction (3/16)}″ to ¼″ long, Yellow-Green Group     144B, funnel shaped, persistent, and pubescent. The five imbricated     sepals are lanceolate and joined at the base to form a cup. As the     buds swell the bud sheath matures to a Greyed-Orange Group 165A,     falls off, and reveals the flower color White Group 155D to Red     Group 56C. -   Flowers: Perfect, single, glabrous, open funnel shaped, 2½″ to 3″ in     diameter by 2¼″ to 3″ in depth, borne on current season's growth,     non-fragrant; they last on the plant in the garden 5 to 6 days.     Flower color is mostly White Group 155D with occasional flowers     being partially or wholly Red Group 56D. These color designations     are for both the upper surface and the undersurface. A plant with     these color variations is not fixed except in the sense that it will     continue to produce a known range of variants. There are five petals     which are fused at the base, elliptic to obovate, and have wavy     margins. These petals are 1¾″ to 2¼″ long, ¾″ to 1¼″ wide, and have     rounded apexes and entire margins. Three out of five petals are     dotted with Red-Purple Group 71C. There are 5 to 9 stamens which are     1¼″ to 1¾″ long. The filaments are Red-Purple Group 56B, the anthers     are Red Group 44A, and the pollen matures to Yellow Group 11B. The     pistil is single, 1¾″ to 2¼″ long and Red Group 51A. The ovary is     densely glandular-setose and has five locules. The capsule matures     in about 5 months, in Independence, La., to about ¼″ to ½″ long; it     has a persistent style, is Yellow-Green Group 147A, and contains     from 100 to 400 nonwinged seeds. Normally fruit set is not heavy.     There is a 2 to 3 week flowering period in April in Independence,     La. Flowering resumes in early July as the new buds mature and     continues until frost which can be as late as November or December     in Independence, La. Azaleas blooming at this time of year attract     butterflies in profusion. -   Culture: Grows well in a wide range of conditions, tolerates sun to     shade. Prefers a moist, well-drained soil that is rich in organic     matter. Responds well to mulching and medium applications of     fertilizer; prefers ph 5.0 to 5.5. Very little pruning is needed;     adaptable to container and above ground planters; makes a good     foundation plant or informal hedge with excellent foliage and flower     contrast. Ideal for coastal regions and warmer parts of Piedmont.     Propagated with semi-hardwood cuttings in late spring through the     summer. -   Pests: Lace wing and spider mites can be a problem. 

1. A new and distinct variety of Azalea plant named ‘Robled’, as illustrated and described. 